Formula
BMI = weight in kilograms ÷ (height in metres × height in metres). Height in metres = height in centimetres ÷ 100.
Health
BMI Calculator
Calculate adult body mass index from weight and height, with the formula, category band and limitations shown clearly.
Calculator
Working calculator
Live result22.86 kg/m²70.0 kg ÷ 1.75² m · adult healthy weight screening band
Formula used
BMI = weight in kilograms ÷ (height in metres × height in metres). Height in metres = height in centimetres ÷ 100.
This is the method behind the answer, so the result can be checked rather than simply trusted.What-if check
BMI by nearby weight
Height stays fixed while nearby weights are compared. This keeps the denominator visible and makes the printed record useful as a worksheet or screening note.
| Weight | BMI | Adult screening band |
|---|---|---|
| 65.0 kg | 21.22 kg/m² | healthy weight |
| 70.0 kg | 22.86 kg/m² | healthy weight |
| 75.0 kg | 24.49 kg/m² | healthy weight |
Visual proof
Adult BMI screening scale
The printable report works as a classroom worksheet, personal tracking note or appointment preparation record because it keeps the formula, inputs, band and limitations together.
Visual grid
This number is one point on a larger pattern
BMI is not just a final answer. It is a step on a line: before and after, input and output, assumption and result.
Micro-timehours, minutes, shiftsHuman scaledays, weeks, projectsMacro-timemonths, years, calendars
InputFormulaResult
22.86 kg/m²CalculationTime keeps the path visible: the input, the method and the final number belong together.
Printable calculation report
Result: 22.86 kg/m². Assumption: The formula uses metric BMI arithmetic for adults: kg ÷ m².
- Weight
- 70
- Height
- 175
- Comparison weight
- 75
- Page/date context
- 2026-05-16 UTC page version
- Page URL
- https://calculationtime.com/calculators/bmi-calculator
Worked example
For 70 kg and 175 cm: convert 175 cm to 1.75 m. Square the height: 1.75 × 1.75 = 3.0625. Divide 70 by 3.0625 to get BMI 22.86 kg/m².
Professional note
Master’s Tip: print the BMI result with the source height and weight, not just the final number. A BMI band can be useful for a classroom worksheet or screening record, but it should not replace medical advice, growth charts or a clinician’s assessment.
Regional and unit assumptions
Standard or basis: this page uses the common adult BMI formula kg/m² and widely used adult screening bands: under 18.5, 18.5–24.9, 25.0–29.9 and 30.0 or above. It does not provide diagnosis, treatment or personalised health advice.
Assumptions and limitations
- The formula uses metric BMI arithmetic for adults: kg ÷ m².
- Height must be greater than zero because the formula divides by height squared.
- Adult BMI categories are screening categories, not a diagnosis or individual health assessment.
- BMI can be misleading for children, pregnancy, athletes, older adults and people with unusual body composition; use clinical guidance for health decisions.
Methodology & Accuracy
How this calculator is checked
CalculationTime pages are built around visible arithmetic: the formula, assumptions, worked example and practical limitations are shown so the result can be checked rather than simply trusted.
Formula used
BMI = weight in kilograms ÷ (height in metres × height in metres). Height in metres = height in centimetres ÷ 100.
Standard or basis
Standard or basis: this page uses the common adult BMI formula kg/m² and widely used adult screening bands: under 18.5, 18.5–24.9, 25.0–29.9 and 30.0 or above. It does not provide diagnosis, treatment or personalised health advice.
Where a calculator follows a named legal, trade or industry standard, that standard is cited visibly. Otherwise the page uses transparent general arithmetic and states its limits.Master's Tip
Master’s Tip: print the BMI result with the source height and weight, not just the final number. A BMI band can be useful for a classroom worksheet or screening record, but it should not replace medical advice, growth charts or a clinician’s assessment.
Related calculators
Questions
How do you calculate BMI?
Convert height to metres, square that height, then divide weight in kilograms by the squared height.
What is the BMI formula in metric units?
BMI = weight in kilograms ÷ height in metres squared, often written as kg/m².
What BMI category is considered healthy for adults?
Common adult screening bands place 18.5 to 24.9 in the healthy-weight range, but individual health needs clinical context.
Is BMI a diagnosis?
No. BMI is a simple screening measure. It does not directly measure body fat, fitness, muscle mass, pregnancy status or individual medical risk.
Can children use this BMI calculator?
The arithmetic can be calculated, but children and teenagers need age-and-sex percentile charts rather than adult BMI category bands.
Calculation note
BMI is a compact height-and-weight index. It is useful because the formula is simple and repeatable, but the page keeps its limits visible so the number is not mistaken for a diagnosis.
BMI is an index, not a direct body-fat measurement
BMI compares weight with height squared. That makes it easy to calculate across large groups, but it does not directly measure body fat, muscle, bone density or individual health risk.
Adult category bands are screening bands
Public-health pages commonly present adult BMI bands such as underweight, healthy weight, overweight and obesity. Those bands can help with screening and education, but personal interpretation should consider age, sex, ethnicity, medical history, body composition and professional advice.
Why printable records matter
A printed BMI note should keep the height, weight, date, formula and limitations together. That makes the result useful as a classroom worksheet, personal tracking record or appointment note without pretending the calculator is a clinician.
Sources and further readingCDC: About Adult BMIWHO: Body mass index - BMI